A restructure of the returned 'get_redis_info' has been done.
The function is now returning a set of host/port collection
based on the required service: pair, central, ha or norep.
This change takes also into account the migration of the redis
configuration parameters from config.yml to constant.yml.
In particular the ports of the redis/valkey services are now
fully defined under the database.xxxx.redis_... keys.
The commit also consider the case of the multi-site config
where the connections to the ha nodes has to be switched to
the port used by haproxy service.
Change-Id: Ie33f2630fde9926391dd5906c0518b0618887621
Marco Capetta